1,986 research outputs found
Temperature effects on the magnetization of quasi-one-dimensional Peierls distorted materials
It is shown that temperature acts to disrupt the magnetization of Peierls
distorted quasi-one-dimensional materials (Q1DM). The mean-field finite
temperature phase diagram for the field theory model employed is obtained by
considering both homogeneous and inhomogeneous condensates. The tricritical
points of the second order transition lines of the gap parameter and
magnetization are explicitly calculated. It is also shown that in the absence
of an external static magnetic field the magnetization is always zero, at any
temperature. As expected, temperature does not induce any magnetization effect
on Peierls distorted Q1DM.Comment: 11 pages, 2 figure
HF radar for port management: case study in the Port of Rotterdam
The phased array HF ocean radar installed at the Port of Rotterdam gives good quality near real-time information on surface currents for port management. This paper examines the potential to infer current profiles from HF radar and wind station data using prior knowledge of the site. It is shown that tidal currents follow a logarithmic boundary layer profile, and the wind-driven currents have an approximately exponential profile. These two models are combined to estimate the current profiles
Laju Pengendapan Sedimen Di Pulau Anakan Muara Sungai Banyuasin Provinsi Sumatera Selatan
Perairan muara Banyuasin Sumatera Selatan, merupakan salah satu muara sungai yang mengalami sedimentasi atau pengendapan, dimana dapat dinyatakan bahwa muara Sungai Banyuasin masih mendapatkan pengaruh yang besar dari aktifitas daratan. Pengendapan yang terjadi sangat berpengaruh terhadap kondisi sekitarnya, diantaranya Pula u Anakan yang terdapat di Muara Sungai Banyuasin. Terbatasnya informasi tentang laju pengendapan di lokasi kajian menjadi dasar pentingnya penelitian ini untuk dilakukan. Penelitian ini bertujuan untuk menganalisis ukuran butir dan karakteristik sedimen serta menganalisis laju pengendapan sedimen yang terjadi di muara Pulau Anakan. Penelitian ini dilaksanakan pada Mei – Juni 2013. Penelitian ini dimulai dengan pengambilan sampel sedimen di lokasi kajian menggunakan sedimen trap yang telah dimodifikasi, yang berfungsi menangkap sedimen yang berada pada dasar serta permukaan sungai sehingga bisa ditentukan karakteristik maupun laju pengendapan di lokasi kajian sekaligus mendapatkan sumber sedimen tersebut berasal yang kemudian dilanjutkan dengan analisis sampel di laboratorium. Hasil penelitian menunjukkan karakterisitik sedimen pada Pulau Anakan didominasi lumpur dan lumpur berpasir dengan dominansi sedimen berasal dari masukan sungai/daratan. Laju pengendapan yang terdapat di Pulau Anakan sebelah Utara adalah 2,645 x 10-11m3/s, untuk sebelah Barat Daya adalah 1,421 x 10-10m3/s dan sebelah Selatan adalah 1,625 x 10-9m3/s, dimana laju pengendapan tertinggi berada pada bagian Selatan Pulau Anakan, yang berhadapan langsung dengan muara Sungai Banyuasin dan Sungai Lalan
Evidence for competition between the superconducting and the pseudogap state in (BiPb)_2(SrLa)_2CuO_{6+\delta} from muon-spin rotation experiments
The in-plane magnetic penetration depth \lambda_{ab} in optimally doped
(BiPb)_2(SrLa)_2CuO_{6+\delta} (OP Bi2201) was studied by means of muon-spin
rotation. The measurements of \lambda_{ab}^{-2}(T) are inconsistent with a
simple model of a d-wave order parameter and a uniform quasiparticle weight
around the Fermi surface. The data are well described assuming the angular gap
symmetry obtained in ARPES experiments [Phys. Rev. Lett {\bf 98}, 267004
(2007)], where it was shown that the superconducting gap in OP Bi2201 exists
only in segments of the Fermi surface near the nodes. We find that the
remaining parts of the Fermi surface, which are strongly affected by the
pseudogap state, do not contribute significantly to the superconducting
condensate. Our data provide evidence that high temperature superconductivity
and pseudogap behavior in cuprates are competing phenomena.Comment: 5 pages, 3 figure
Zero-field superfluid density in d-wave superconductor evaluated from the results of muon-spin-rotation experiments in the mixed state
We report on measurements of the in-plane magnetic penetration \lambda_{ab}
in the optimally doped cuprate superconductor (BiPb)_2(SrLa)_2CuO_6+\delta (OP
Bi2201) by means of muon-spin rotation (\muSR). We show that in unconventional
wave superconductors (like OP Bi2201), \muSR experiments conducted in
various magnetic fields allow to evaluate the zero-field magnetic penetration
depth \lambda_0, which relates to the zero-field superfluid density in terms of
\rho_s\propto\lambda_0^-2.Comment: 4 pages, 5 figure
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